Sphingid moths are
insect versions of hummingbirds. Both hover in midair by rapid wing beats
while drinking nectar with extremely long tongues (hummingbirds) or tube-like
mouthparts (moths), usually from elongated trumpet-shaped flowers that
have evolved their shape to exclude generalist pollinators like honeybees
in favor of more the specialized, exclusive pollination services of hummingbirds
and sphingid moths. In return for a supply of nectar reserved for them,
these animals do a good job of carrying pollen from flower to flower.

Some smaller species of sphingid moths fly about
during the daytime just like hummingbirds, but most of the larger ones,
including this white-lined sphinx, Hyles lineata (here feeding
on nectar from phlox in the photographer's perennial flower beds), are
usually nocturnal. The larger ones make a whirring sound with their wings
that is often confused with that of hummingbirds.

The white-lined sphinx is common in our region.
Its caterpillars feed on portulaca and a wide variety of horticultural
plants including apple, pear, plum, grape, tomato, melon, buckwheat and
turnips; as well as weedy species such as chickweed, purslane, and evening
primrose. The adults fly in mid summer to early autumn, and there is more
than one generation per year. The insect over winters underground as a
pupa.

References

Dunn, G. A. 1996. Insects of the Great Lakes Region.
University of Michigan Press.

Milne, L. and M. Milne. 1980. The Audubon Society Field
Guide to North American Insects and Spiders. Alfred A. Knopf, NY.